Abrasive disk



Oct. 29, 1929. A. J. DOERMANN ABRASIVE DISK Filed March 24, 1928 u. V a w Patented Oct. 29, 1929 UNITED STATES PATENT OFFICE ALBERT J. DOEBMANN, OI CHICAGO, ILLINOIS ABRASIVE DISK This invention relates to improvements in abrasive disks and more especially relates to .such disks composed of powdered abrasive and cement. For example, the abrasive may consist of ground or powdered carborundum, emer flint, or any similar suitable substance, and e bound together by an suitable cement, such as, for example, ba elite resin.

Among the features of my invention is the provision of means for fastening the disks to a metal backing or plate.

In that form of device embodying the features of my invention shown in the accompanying drawing, Figure 1 is a view in side elevation, Fig. 2 is a view taken as indicated by line 2 of Fig. 1, Fig. 3 is a vertical sectional view of the mold used in forming my improved disk, Fig. 4 is a view taken as indicated by the line 4 of Fig. 2, and Fig. 5 is a vertical sectional view of a modified form.

As shown in the drawings, 10 indicates the mandrel or shaft of an ordinary grinding machine, and 11 the usual collar thereon to which is attached the ordinary steel disk 12. The disk 12 is adapted to carry the abrasive disk.

In the making of my improved disk, I provide a circular metal backing 13 provided with a plurality of holes 14, preferably slightly undercut, as indicated by 14. Threaded into the backing 13 is also a plurality of studs 15 having their inner ends bored out, as

indicated by 15.

16 indicates the mold in which the disk is formed. In the bottom of this mold is first placed the metal backing 13, the outer ends of the studs 15 extending through holes 16 in the bottom of the mold. 17 indicates a layer of cement which is first applied to the backing 13 and permitted to go down in the holes 14 and also in the holes 15 in the ends of the studs 15. Such cement, for example, may be bakelite cement. After the layer of cement 17 is applied, the mold is filled with a mixture of abrasive and cement, as indicated b 18. For example, I may use ten pounds of a rasive to from sixteen. to twenty-six ounces of cement, which may be bakelite cement, or bakelite resin. I have also found it of advantage to first treat the powdered abrasive Application filed March 24, 1928. Serial No. genus.

with a suitable hard drying oil, for example, China wood, or tonga wood oil. Coating the abrasive grains with such oil assists in causing the cement to adhere to the same.

After the mixture of abrasive and cement has been put in the mold, as shown in Fig. 3, the same is placed in an oven and baked at a proper temperature, in the usual manner, for a suflicient length of time, as is well known 1n the art, preferably without the use of any pressure.

In Fig. 5, I have shown a modified form. In the device here shown, the disk, as indicated by 18", is first completely made in any well known manner and then cemented to the metal backing 13 by means of the cement 17". In attaching the disk in this manner I may use bakelite cement, applying a coating to the disk 18* and also to the metal backing 13", and then place the disk on the metal plate and bake for one hour at approximately 350 F. The metal backing 13 may be supplied with ordinary studs 15 to be used to attach the same to the disk 12 of the grinding machine.

The abrasive disk shown in Figs. 1 to 4, when completed, may be attached to the disk 12 of the grinding machine by inserting the outer ends of the studs 15 through such disk and applying the nuts 19.

While I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended claims, in which it is my intention to claim all novelty inherent in my invention as broadly as possible in view of the prior art.

What I claim as new, and desire to secure by Letters Patent, is:

1. An abrasive disk comprising; a metal backing; outwardly projecting studs fastened in said backing, the inner ends of said studs being cored out; and a layer of a mixture of abrasive material and cement fastened to the face of said backing, said mixture extending into the cored out ends of said studs.

2. An abrasive disk comprising; a metalbackin ;utward1y projectin studs fastened in said acking, the inner en of said studs being cored. out; a layer of cement on the face of said backing and extending into the 5 cored out ends of said studs; and a layer of a mixture of abrasive material and cement lying over said first mentioned layer of cement.

In witness whereof, I have hereunto set my hand this 22nd day of March, 1928.

ALBERT J. DOERMANN. 

